Field of the Invention
The present invention is in the technical field of crop protection compositions which can be employed against unwanted vegetation, for example by the post-emergence method in sown and/or planted crop plants, in fruit plantations (plantation crops), on non-crop areas (e.g. squares of residential areas or industrial sites, rail tracks) and on lawns. In addition to the single application, sequential applications are also possible.
Description of Related Art
The present invention relates to a herbicide combination comprising at least two herbicides and its application for controlling unwanted vegetation, in particular a herbicide combination comprising at least pelargonic acid and at least one ALS inhibitor selected from the group consisting of iodosulfuron-methyl, foramsulfuron, mesosulfuron-methyl, flazasulfuron, amidosulfuron, ethoxysulfuron and thiencarbazone-methyl.
Herbicidally active fatty acids are known from the prior art (e.g. WO01/05472).
A compound from the substance class of the ALS inhibitors inhibits the enzyme acetolactate synthase (ALS) which is responsible for the biosynthesis of branched amino acids such as L-valine, L-leucine and L-isoleucine. Therefore, this substance class—in addition to other substance classes—is, according to its mechanism of action, assigned to the group of the ALS (acetolactate synthase) inhibitors (see also http://www.hracglobal.com/Portals/5/moaposter.pdf). The ALS inhibitors include, for example, the sulfonylureas (see also, for example, “The Pesticide Manual” 15th, Edition, British Crop Protection Council 2011). These herbicides are in particular frequently applied on fields cultivated with soybeans and cereals. Uptake of these herbicides is via the roots and leaves.
The herbicidal activity of such herbicides against harmful plants (broad-leaved weeds, weed grasses, cyperaceae; hereinbelow together also referred to as “weed”) is already on a high level, but generally depends on the application rate, the respective preparation form, the respective harmful plants to be controlled or the spectrum of harmful plants, the climatic and soil conditions, etc. Further criteria in this context are duration of action, or the breakdown rate, of the herbicide, the general crop plant compatibility and speed of action (more rapid onset of action), the activity spectrum and behavior toward follower crops (replanting problems) or the general flexibility of application (control of weeds in their various growth stages). If appropriate, changes in the susceptibility of harmful plants, which may occur on prolonged use of the herbicides or in limited geographical regions (control of tolerant or resistant weed species), may also have to be taken into account. The compensation of losses in action in the case of individual plants by increasing the application rates of the herbicides is only possible to a certain degree, for example because such a procedure reduces the selectivity of the herbicides or because the action is not improved, even when applying higher rates.
Thus, there is frequently a need for targeted synergistic activity against specific weed species, weed control with better overall selectivity, generally lower amounts of active compounds used for equally good control results and for a reduced active compound input into the environment to avoid, for example, leaching and carry-over effects. There is also a need for developing one-shot applications to avoid labor-intensive multiple applications, and also to develop systems for controlling the rate of action, where, in addition to an initial rapid control of weeds, there is also a slow, residual control.
A possible solution to the problems mentioned above may be to provide herbicide combinations, that is mixtures of a plurality of herbicides and/or other components from the group of the agrochemically active compounds of a different type and of formulation auxiliaries and additives customary in crop protection which contribute the desired additional properties. However, in the combined use of a plurality of active compounds, there are frequently phenomena of chemical, physical or biological incompatibility, for example lack of stability in a joint formulation, decomposition of an active compound or antagonism in the biological activity of the active compounds. For these reasons, potentially suitable combinations have to be selected in a targeted manner and tested experimentally for their suitability, it not being possible to safely discount a priori negative or positive results.